Junction-box.



C. W. DAVIS.

JUNCTION BOX. TION FILED AUG. 27, 1910 RELNBWBD DBO. 17, 11912.

Patented Aug. 18, 1914,

3 SHEETS-SHEET l,

FIEL' 1%.@ A. A f RQ. m M" ./A @L u Oi( L KMK /QZSw/@ I NvENToR C. W.DAVIS. JUNCTION B0X. APFLIUATION FILED AUG. 27, 1910. RENBWBD DB0. 17,1912'.

1 1 07,499 Patented Aug.

FIEZ..

3 SHEETS-SHEET 2.

WITNESSESC 1 ,107,499. Patented Aug. 18, 1914.

3 SHEETS-SHEET 3.

FIGB- WIT E I N SSES INVENTOFI UNITED sTATEs PATENT OFFICE.

l CHARLES w. DAVIS, or EDGEWORTH; PENNSYLVANIA, AssIGNon To STANDARDDERGROUNDCABLE COMPANY, or PITTSBURGH, PENNSYLVANIA, A CORPORATION orPENNSYLVANIA.

- JUNCTION-Box.

specification of Lettere Patent. Patented Aug', 18, 1914,

Application mea Augustin', 191o,serie1No. 579,334. Renewed December 17,1912'. serial No. 737,309.

`To all whom, it may concern Be it known .that I, CHARLES W. DAVIS,residing at Edgeworth, in the county of legheny and State .ofPennsylvania, a citizen of the United States, have invented ordiscovered certain new and useful Improvements in J unction-Boxes, ofwhich improvements the following is a specification.

f'AMy invention relates to improvements in junction boxes for electricaltransmission cables, and theobjectsof my invention are simplicity ofstructure and .facility of ,i11- stallation. 'y

My inventionis illustrated in the accompanying drawings which form' partof thls specification and in which* F igure l is a plan of the boxbefore the insulating closure and top portion of the casing' ot-hhereinafter: described) have been assembled; Fig. 2 is a section takenon the line H II of Fig. l; Fig.3 is a section lto designate the partswhiclrappear in the several figures. j

'The/junction box I have invented is particularly applicable to cablescarrying such high-voltage currents as are liable to jump from oneconductor `to another; and it is also particularly designed forunderground ca'- bles, wherethe `unction box nlust be placed in amanhole w ere working conditions are vnecessarily limited by llack ofspace,- In i meeting these two conditions, I have de- 4 signed ajunction box wherein all' the conductors areinsulated, either by vbeingsurrounded by walls of insulatingimaterlal or by'being immersed in aninsulating corn-` p'ound, proper precaution being taken in the lattercase to provide room :for the expansion of said com ound, duetoincreasein temperature un( er., .working conditions,

Furthermore, all the/parts of the box may be assembled in the s op andpacked wlth said compound, leaving only the hereinafter describedflexible leads to be attached to the cable in the manhole. The'saidattachmentor detachment may be made without .in any way affecting theintegrity of the insula- 'ltion of the box proper.

The junction box consists 'of a casing l having a removable 4cover 5,and divided in-'A ternally and beneath the closure of the cover by apartition, which partition separates the space within the box intoseparate chambers. This partition 1s composed, at least through lasubstantial part of its extent, of insulating, material, and throughsuch insulating 'wall one or more pairs of binding posts extend. Thechamber beneath the partition, that is, on the side opposite theremovable cover, is the chamber into which the cables lead throughsuitably'arranged orifices, and the leads from t-he cable conductors arein this chamber connected with the binding 'posts lwhich extendy throughthe partition.

On the opposite side of the artition, that is, the side whichisalternate y covered and exposed by the application and removal of thecover, the pair or pairs of binding posts are connected electrically byconnecting strips or if'desired by fuses.

Referring specifically to the drawings, the partition is shown toconsist of a spider 3, which in this case sustains a. plurality of cupsGformed of insulating material, which 'are open-mouthed toward theremovable cover. In the bottom of eachc'up, and extending through thewall of insulating material which is part of the partition Wall, are apair of binding posts'7, 8. Within the chamber beneath the partition thebinding posts 7 are electrically united with leads 2 which extendthrough oriices in the junction :box wall for connection with theconductors of the cables which are applied to the junction box. Thebinding posts 8 (for in this vcase there are a series of Apairs ofbinding posts) are inter-connected through busbars 11. Y

To the outer wall-.of the` Casin of the junction box, and surroundingeac .orifice through which the cable conductors. gain entrance to thebox, are applied one or more supplemental casings in` the form of 'bells4 upon'which the sheaths of entering'cables may be secured. The bellsare preferably made of .two parts, that Iadjacent the case being of arela-tively rigid material, preferably brass, and the other part beingof afrelatively ductile metal, preferablylead, in the form of a sleeve16. The bi-metallic bell is preferable, because of the difficulty informlng a wiped-solder 'oint between the bell and a cable sheath, i thewhole structure of the-bell be brass.

The chamber beneath the partition into which the cable orifices open isadapted to be' filled with an insulating material; this material willpreferably be what is commonly termed insulative-compound applied hot`and fluid,'but viscid or solid at normal atmospheric temperature. Toeffect the clos- 'ure of the cable `orifice around the leads, and

the several orifices, andwhich,fwhen applied and bolted to place, willeffect a compression of the gasket against the surfaces of the lead andmake a tight closure of each orifice.

An orifice is provided in the wall of the casing, and opening into the'chamberxbeneath the-partition, through which insulating compound may beapplied. The drawings show such an orifice closed by screw plug 23.Means are provided for preventing the complete filling with insulatingcompound of the chamber beneath the partition. Or rather, provisionY ismade that When-the chamber is substantially filled, there shall remaineither within the walls of the box itself or in a supplementalv andconnecting chamber, an air space" to serve as a cushion; for thecoefficient of expansion of insulating compound such as is commonly usedis great, and so great that if a junction box chamber be completelyfilled with compound the expansion which may occur under varyingtemperature may disrupt the'box when in service. My preferredconstruction in this regard is particularly shown Figs. 2 and 3, and analternative construction is illustrated in Fig. 6. v My preferredconstruction consists in rovidin a filling orifice with an inwarextendin li 21 of such length that when the box 1s p aced in theposition indicated in Fig. 3 for the pur-A pose of filling, thislip 21vwill, as the insulating material is poured in, trap a body' of air inthe upper part of the casing, which body of air may not be displaced bypouring in more'fof the fluid compound, and this body of air will serveas a cushionfor the purpose Il I have described. The alternative shownin AF ig. 6 does not involve such a depending lip kas is illustrated inFigs. 2 and 3, although a slightenl'argement or boss is, for structuralreasons, desirable 'at the point where the opening is made; but a closedair chamber 22 is tapped intothe orifice. This chamber is removable toallow the filling of the junction box to be effected, and when thefilling has been performed, it is applied to o Vthe insulating fillercompresses the air v cushion beyond a certain point. Such an arrangementconsists of communication preferably effected through a pipe 30, andsuch communication being normally interrupted by Vaclosure 31 of anypreferred form which under abnormal pressure will open. Preferably theclosure is in the form of a frangible septum of moisture-proof material,,such as varnished cloth or paraffin pa er.

ne feature remains to be noted of the arrangement of the parts beneaththe partition.- Aprons 24 are preferably provided, formed of insulatingmaterial', and conveniently made part of the insulating plates orsections 6 of the partition itself, which extending between the bindinposts which form the pairs, prevent electrical discharge between them orbetween approaching conductors.

Referring. now to the chamber o'n the upper side ofthe partition, thatis the side which is closed by the removable cover, the structuralfeatures consist in means for preventing electric discharge from thecurrentcarryin members on that side of the partition, to the removablecover; second, where' a plurality of pairs of binding posts are present,means for preventing electric discharge from one pair of binding poststo another; and third, ay means for guarding from disruption thejunction box casing itself, in the event of the explosion of a fuseemployed to connect apair of binding osts.

The means for preventingelectrica discharge from the binding posts tothe cover, consist of a screen 13, preferably in the form of anasbestos-covered board, which is arranged `within the junction box toextend between the adjacent ends of the binding posts and the cover ofthe junction box. I have hereinabove spoken of the insulating portionsof the partition as open-mouthed cups, 6. So far as their function informing the drawingsthe several pairsotl binding posts may beconnectedeither' by connecting stri s 10, or by fuses 10a.

he means against disruption of the casing itself 1n consequence4 o theexplosionv of a fuse, consist of an orifice inthe"- wall of the casingopening from the chamber above the partition and a closure for'that,orifice which is disruptable under the pressure of lexplosion. such as Ihave alluded to. In Fi 4 and 5 are shown alternative forms o closure.

The `closure of Fig. 4 consists of a septum- 20 of pro er material,which maybe varnished fa ric or oiled paper, which is iIn` pervious toymoisture, but which under the pressure of ex losion of a fuse, willburst outwardly andp relieve the ressure.-r closure 'shown in Fig. 5consists of an outwardly opening valve 18, which may be held to itsseat, by any Well-known means, for example by` spring pressure, andwhich, yielding under the stress of explosive expansion, opens` torelieve the pressure within the chamber. I further provide against theingress of water through this pressure relief oricein case arising ofwater in a manhole should effect the submergence of the junction box. Tothis end a tube' 17 surrounds theorice on the outsideof the boxandlplrojects downwardly to form a chamberwithin which air is trappedwhen Water rises around the junction box, and Vthe air 4so trappedguards the orifice from the entrance of water.` It will be understoodthat it better to form this onifice in thatwall of the junction boxwhich when the box is installed is lowermost, in order that thisairtrapping tube ma be most readily and simply arran ed. n the case ofthe Ifrangible septum i ustrate'd in Fig. 4, the septum may, 1f desired,be protected against disrupff d l .box and connected with a neutral busbar tion by pressure from without, such as'may be 'occasloned bysubmergence of the junction box, by a screening 19 y'lying againstemployed for protecting The' "lation and repair.

binding posts in each compartment. In l other words, I may have aplurality of cups in a single piece. lWhile the spider'- 3 may support asingle cup, it ispreerred for compllcated systems to provide a numberof'cups';

arranged in a double row, and place each pair of binding posts in a`positiony transverse .to the line of succession of individual cups. Bysuch arrangement the inner binding posts of opposite pairs areconvenient position for interconnection by busbars or otherwise, and-the outer f posts 'nearer the walls ofthe box are provided with theilexible leads which' pass through the 'orifices in the Walls. d

It will be` understood that theshape of the junction box, the "number ofcups'fthe number ot compartments in each cup, the number ofcables-entering and leaving the box, the number of conductors in eachcable, are features which admit of indefinite, variation. f

The assemblin ot the parts is effected in this manner. he cup or lcupswith the binding posts in place are mounted in the spider and thedesired vconnections are made. Within the cups .the strips 1'0 orfuses10 are applied, and the opposite ends of .the binding posts are eitherinterconnected 'as' by bus-bars 11 or are provided with ltlexible leads2. The partition is then brought to position in the casing, andas itisapplied the flexible leads 2 are carried through the proper orifices.The artition` is then securedl in place, the pac 'n -`is applied in theorifices, and the chamber eneath the Vpartition filled withinsulating-compound. The cover 5 is' then lapplied, and 'the box isready for installation. l

It willbe observed ofthe -box as thus far described, :thatthear'rangement while simple is economical of space, and that the partsare readily accessible fory purposes of instal-I It, will. further beobserved that the `structure is g such that the whole box may beassembled in thevv shop, and that in'stallat1on may be effected merelyby making `ordinary connection between the conductors of the cables andthe leads, and rty'seeuring the cable sheathstothe bellslt.

hedrawings show a cable 15 entering the 25.` The sleeve 16 of the lbells4 may be closed, as is particularly .illustrated at 16,

Fig. 3, to protect ,the end of a ylead 2 secured 1n place; and in suchcondition the box may be shipped. The closed end of the sleeve will beopened when vinstallation is to be made. It will be understood that notonly is the partition removable as a Whole,` but the individual cups areseparately removable, which is a feature of distinct advantage for'purposes of repair or introduction of or removal of additional lines tothe junction box. When in use any face of the box may open depeiidin bethe top, but for convenience of illustration the side uppermost in thedrawings is considered the top.

I claim herein as myinvention:

1. In a junction box the combination of a casing with a removable lid, apartition seating itself beneath said lid and when the parts arefinplace dividing the space Within the casing into separatev chambers, aplu'- rality of cups formed ofinsulating material contained in said.partition and Openmoiitlied toward said lid, and current-carry' ingmembers Within said cups, substantial as described. f 1

2. In a junction box the combination of a casing, a partition mountedtherein and dividing the space Within said casing into a plurality oichambers, said partition consisting of ay spider and a plurality of`plates of insulatingy material carrying pairs of binding posts mountedin said spiderand severally removable therefrom, substantially asdescribed.

3. In a junction-box for electrical conductors containing an explosivefuse vand provided with an orifice in its Wall, ajdisrupt able closurefor said orifice, the said orilice provided with a water-seal consistingof an tubular extension, substantially as descri ed.

LI. Ina junction-box for electrical conduo tors, the combination of a'casing, a partition dividing the space Within the casing into separatechambers, a body of insulating material Within the chamber on one sideof said partition, an air chamber in communication, with theinsulating-materialvfilled space, an explosive fuse` Within the chamberon the opposite side of said partitionthe Wall of the portion of saidjunction box casing inclosing said fuse-containing chamber beingprovided with an orifice, a disruptabley closure for said orifice, saidori- Alice provided' with a tube extending into said air chamber,substantially as described.

5. As anv article of manufacture, -a junction box having a lid andprovided with an orifice in its wall, a body of insulation lilling :aportion only of said box opposite said lid, any electrical conductorpassing Jfluidtiglit through said orifice and through said body ofinsulation and into the unfilled portion of said box, anda closedsupplemental casing inclosing the outer end of said conductor andsecuredexternally to said junction box Wall.

' 6. As an article of manufacture, a junction box having a lid, apartition dividing the space Within said box in to open and closedchambers, said open chamber being adjacent to said lid and said orificeopening into said inclosed chamber, a body of insulating compound Withinsaid closed cliaiiiber, an electrical conductor passing iuidtightthrough said orifice in the box wall and through said compound and saidpartition into said open chamber, and a closed supplemental casinginclosing the outer end of saidconductor and secured externally to saidjunction ybox wall.

7. The combination with a junction box having an orifice `in lits Walland provided with interconnected electrical conductors and having anelectrical conductor extending through said orifice in its Wall; of aclosed supplemental casing inclosing the outer cndvof said conductor andsecured externally to said junction box casing, the

outer closed end of said casingbeing constructed of soft metal and beingconvex outwardly. v

S. ln a junction box, the combination of a casing having a lid, apartition seating itself beneath said lid and dividing the space within'said casing into separate chambers, a plurality of insulatedcompartments formed upon said partition .and open-mouthed toward said11d, and a plura ity of electrical conductors extending through saidpartition into each of said compartments.

In testimony whereof, I liavehereunto set my hand.

CHARLES W. DAVIS. Witnesses:

G. G. TiziLL, BAYARD Il. CHRISTY.

